by Michele Chabin, Special for USA TODAY

by Michele Chabin, Special for USA TODAY

JERUSALEM - A bomb police say was planted by Palestinian terrorists exploded on a public bus shortly after it was evacuated Sunday, resulting in no serious injuries.

"Based on the findings at the scene by bomb disposal experts, it was a terrorist attack," police spokesman Micky Rosenfeld told the Associated Press. "We're continuing to search the area for suspects."

A passenger on the No. 240 bus in Bat Yam, a town south of Tel Aviv, spotted a suspicious-looking backpack and alerted the driver. Detecting wires inside the bag, the driver evacuated the passengers and called the bomb squad.

Within minutes of the evacuation, a member of the bomb squad was slightly injured when the bomb he was attempting to defuse exploded, according to Israeli media reports. The blast blew out or shattered all of the bus' windows but caused no other injuries.

Rosenfeld told the AP the nature of the target and the nature of the device led authorities to determine that militants, not criminals, were behind the bombing. He declined to elaborate, and there was no immediate claim of responsibility.

The blast comes at a difficult time for U.S.-brokered peace negotiations between Israel and the Palestinians, who returned to the negotiating table during the summer for the first time in half a decade. U.S. Secretary of State John Kerry, who has been spearheading the mostly stalled talks during multiple visits to the Middle East, is expected back in the region later this week.

Israelis experienced a wave of fatal bus bombings and other terror attacks during the first and second Palestinian uprisings, which petered out around 2004. Despite a relative lull in attacks, in 2011 a bomb exploded at a Jerusalem bus stop, killing a British tourist and injuring 30 bystanders. A November 2012 bus bombing in Tel Aviv injured more than 20.

During the past couple of years an escalation in Palestinian rock-throwing attacks in Jerusalem and the West Bank has resulted in several injuries and some deaths.

Aviv Oreg, former head of the Global Jihad desk of the Israel Defense Forces, said the fact that no Israeli passengers were hurt in Sunday's attack bodes well for Kerry's ongoing efforts to make substantial gains at the negotiating table.

"Israel probably won't retaliate" so as not to sabotage Kerry's peace attempts, Oreg said. "Had there been several casualties, Israel would feel compelled to retaliate."

Oreg, founder of "CeifiT," an investigative consulting firm that specializes in counter-terrorism analysis, said the bus bombing was likely carried out by a Palestinian terror group in response to "Israeli activities" in the West Bank.

In October, Mohammed Assi, an Islamic Jihad militant whom Israel said was responsible for the 2012 bus bombing, was killed in an exchange of fire with Israel Defense Forces at a cave where he was hiding out near Bil'in, west of Ramallah.